a. Field Of The Invention
The present invention relates to improvements in apparatus mounted on a railroad track survey car for determining the difference between the actual and a desired position of the track whereon the car moves.
B. Discussion Of The Prior Art
U.S. Pat. No. 3,610,894, dated Oct. 5, 1971, proposes a peak analysis system wherein the error signals are measured only between maxima and minima, without reference to a datum line, which sometimes leads to incorrect results. All errors above and below the datum line (which is not taken into account by the system disclosed in that patent) are evaluated equally, and after a single pass of the survey car over a surveyed track section, no direction or trend, i.e. in which direction the error curve deviates from the datum line, can be detected. Such a trend can be detected only after several passes over the track.
It is the primary object of this invention to provide apparatus which makes it possible to evaluate track position errors according to the direction and magnitude of the deviation of the track from a datum line, and to record and store this information.